Stud driving tool



July 21, 1953 M. H. WALKER STUD DRIVING T OOL Sheets-Sheet l Filed nay e, 1951 INVENTOR.

MMM/ WALKER July 2l, 1953 M. H.- WALKER HDRIVING TooL 2 Sheets-Sheet 2 Filed lay 8, 1951 INVENTOR. MEME/1f WAL/(EH ATTORA/s Patented July 2l, 1953 STUD DmvINGfroor.

Merle H. Walker, Ilion, N. Y., assignor to Rem-y ington Arms Company, Inc., Bridgeport, Conn., a corporation of Delaware Application May 8, 1951, Serial No. 225,146

16 claims. (c1. 1-445) This invention relates to an industrial tool which utilizes the power from an explosive car-y tridge to drive studs or fasteners through orinto steel, concrete, brick, wood or other structural material either for joining these materials or for attaching fixtures to the surface of these materials.

More specifically, this invention relates to and has as its principal objects the development of an explosively operated tool which can be operated-with greater convenience, efficiency and safety than any prior explosively operated tool and which can be operated at rates from ten to one hundred times as great as can be achieved with electric, pneumaticfor hand-operated tools.

Although not necessarily limited thereto, this tool may be operated with the greatest convenience and safety with ammunition of the type disclosed in the copending application of Robert T. Catlin et al., Serial No. 217,086, led March 23, 1951, entitled Ammunition The tools most widely used at the present time are all characterized by inconvenience and difficulty in use. Generally, it is necessary to unscrew and remove the barrel for reloading and frequently the operation of the safety devices is so dicult'as to makeit almost impossible to maintain the accurate alignment necessary to drive a fastener in a predetermined location.

The exact nature of the invention as well as other objects and advantages thereof will become more-apparent from consideration of the following specication referring to the attached drawings in which:

Fig. 1 is a longitudinal sectional view through my improved tool, the ring pin being shown in cocked position.

Fig. 2 is an end elevational View partially in section on the line 2-2 of Fig. 1.

Fig. 3 is a partial sectional view on the plane indicated as 3-3 in Fig. 2, the ring pin being shown in the position it would occupy after ring.

Fig. 4 is a view similar to Fig. 3 in which the frame has been rotated relative to the breech block and housing to retract the firing pin slight- Yly beyond the normal cocked position.

Fig. 5 is a view similar to Fig. 3 in which the frame has been rotated relative to the breech block and housing to completely cock the firing pin and to expose the breech end of the barrel for loading or extraction of a fired shell.

Fig. 6 is a partial sectional view on the plane indicated as 6 6 in Fig. 2, showing the ejector assembly.

Fig. 7 is a partial sectional view on the plane -l-l indicated on Figs. 1 and 2, showing details of the manually operated safety.

Fig. 8 is a 'cross-sectional view on the plane shown by the line 8--8 in Fig. 3.

Fig. 9 is a cross-sectional view on the plane shown `by the lines-" Q in Fig. 4. f

, Fig. l0 is a cross-sectional view on the plane shownby the line Illl0 in Fig. l5.

Fig. 11 is'a partial cross-sectional view on the line ll-ll of Fig. 1.

Fig.r 12 is a partial cross-sectional view on theline I2--I2fof Fig. 6. i v

Referring to the drawings by characters of reference, it will be Vnoted that the tool comprises a barrel I threadably or otherwise 'secured at its breech end to a frame plate 2. A breech block 3 is hinged to the :frame plate 2 by a hinge bolt 4 passing through both block and plate axially parallel to the barrel on whichthe breech blockA and frame "plate are capable of relative rotation far enoughto expose the breech end of the barrel. When the breech block is in alignment with the frame and Vclosing the breech of the barrel, a breech'hook 5 engaged in a closely fitting groove in the breech block 3'and secured to the breech block 3-by any convenient means such as a furnace brazing operation is slidably engageable in a groove 5a in the frame plate. f Thus, thev hinge pin 4 and thebreech hook 5 provide substantially diametrically opposed members resisting axial separation of the breech block and frame plate -and having ample strength to withstand the forces of discharge of any cartridge which may be used. 'An arcuate slot 6. Figs. 8, 9 and 10, in

the frame lplate receives a.` breech stop"A pin 1 mounted in the 'breech block which limitsv'the swinging movement of the breech block.

i Secured to the frame plate 2 by radially extending screws orother convenient meansis an action tube cover 8 whichhouses and protects certain elements of an automatic safety device and of the cartridge ejecting system, both to be .the familiar and inexpensive rimiire type of cartridge, conveniently that known'as .32 Long rimfire, although obviously centeriire types and other calibers of rimre types may be used without departing from the invention. The firing pin II is therefore supported in alignment with one edge of the barrel chamber I2. Guidance and support for the firing pin is provided by a bushing I3 supported in the rear wall of the housing and by a bore I4 in the breech block 3, while a coil spring I5 engaged between the bushing I3 and a flange I on the firing pin provides the driving force for the firing pin. As may be seen :by comparing Figs. 1, 4, and 5 with Fig. 3, the end of the firing pin is exposed, when cocked, providing for an instantaneous visual check on the readiness of the tool for firing. If desiredthe end of the firing pin may be coated or inlaid with red or other distinctive color to provide a more obvious warning.

The firing pin may be retained in a cocked position by a sear I1 (Figs. l, 3, 4, and 5) swingably supported by a sear screw I8 in the housing and provided with a finger I9 engageable with the forward face ofthe flange I6 on the firing pin I I (Figs. l, 3, 4, and 5). An arm 20 on the sear is extended laterally into a position opposing a cam 2I formed on a slidable trigger bar `22. The trigger bar is provided with a finger piece 23 positioned in the grip IIJ and is normally urged forwardly by a spring 24. Obviously, when the trigger is pulled rearwardly, the cam 2| williY urge the sear toward ilringpin releasingposition.

-Unintentional operation of the trigger is prevented by manually operable safety means which includea safety plunger 25 spring-urged to project from one side of the handle I0 near its intersection with the housing 9.

The safety cam is provided with an eccentric 1 and serrated, knurled, or toothed surface 2 9 which is opposed to a similarly roughened surface 30 on the trigger bar. When the safety button is depressed the eccentric safety cam is rotated to a point such that the roughened surfaces are l out of engagement. Whenever thesafety button is released, the surfaces 29 and 30 are in engagement and any slight rearward movement of the trigger rotates the cam into closer engagement and positively locks the trigger bar. This locking ger bar and will lock the bar if the safety button is released after the trigger has been pulled almost to the releasing point or at any intermediate. point.

lock`3| reciprocably mounted in the housing and urged by a spring 3Ial to project into a position where it extends across and obstructs the path of'firing pin releasing movement of the sear.

its position inV Fig. l, the sear cannot be moved far enough to be disengaged from the firing pin.

AMeans to so move the sear lock is provided by a finger 32 mounted on an action tube 33 which V is slidably mounted on the barrel Within the action tube cover 8. With the breech in closed and locked position corresponding to Figs. l, 3, and 8, aligned holes 34V and'35, respectively in frameand breech block permit the projection of raction is independent of the position of the trig y60 A further safety feature is provided by the sear 5 Unless the sear lock is moved rearwardly from the finger 32 into operative engagement with the sear lock. Unless the breech is properly locked, the holes are out of alignment and the sear lock may not be operated by any means. Obviously, the thickness of the action tube finger must be less than the diameter of the sear lock and the finger must be appropriately positioned or the finger will itself act as a sear lock.

Operation of the action tube is by means of an action tube extension 36 slidable on the barrel and threadably engaged with the action tube. A spring 31, engaged between a shoulder on the barrel and the action tube extension, normally Vmaintains the action tube in a forward position in which the end of the action tube projects beyond the muzzle of the barrel. When the tool is pressed firmly against the surface of a workpiece, the action tube extension will be telescoped .into the cover until the muzzle of the barrel comes into contact with or, if desired, approaches contact with the work. This telescoping movement is-adequate to bring the finger on the action -tube into engagement with the sear lock and to move the sear lock out of opposition to the sear. Should the pressure of the tool against the work surface Ybe relaxed prior to firing, the sear lock will return to a safe position even though the trigger is partially pulled at the time. The sear lock spring 3Ia is of substantial force and with Va partially pulled trigger the sear lock returns I direction. It will be noted that the application of force by the operator to disengage the sear lock is in the opposite direction to the force necessary to pull the trigger, thus minimizing the possibility of inadvertent firing.

When the sear VI1 is operated, the firing pin is propelled into v engagement with the cartridge primer but the relationship of the sear l1 and firing pin flange I6 is such that the edge of the firing pin flange I6 keeps the sear spring 39 from returning the sear to its former position. Under these conditions, the sear holds the sear lock 3I retracted and when the firing pin is-again cocked both the sear-lock spring 3 la and the sear spring 39 urge the sear into holding engagement with the front face of the firing Vpin iiange I6.

The firing pin is cocked each time the breech is opened by a slide 40 which also has the function of ra breech block latch. The operation of the slide is best understood by reference to Figs. 3 to 45, and 8 to l0. Referring to these figures ,and to Fig. 1, it will be seen that the slide is arranged for sliding movement in .ahgrocve 40a in the back face of the breech block and is slotted at 4I to straddle the firing pin in a location forward ofa cooking flange 42 formed thereon. Pin 43 in the breech block supports a torsion spring44 engaged with the slide and urging it continually toward an extreme left hand position -which it occupies as viewed in Figs. 3, 5, 8 and l0. Inthe Fig. l and Fig. 3 positions the breech block vand frame plate are in alignment and in breech closing relationship. In this position a cam pin 45 mounted on the slide is received in a notch 46 `in the frame plate 2 to latch breech block and frame plate`2 in alignment. When the projecting end of the slide is forced inwardly bythumb pressure,l the` cam pin is disengaged from the notch 46 and the frame plate 2 may be turned on the hinge bolt`4relative tof the breech block 3. At the same time, thecam 41 formed on the rear faceof theslideeneasesthe forward face f th flring,.pingflange 42-and starts the retracting of the ri11g,pinso that, its tipmisbehind the front face of :the breechblokand rkmayynot interfere as theframe plate 2 isnswung onfthe hinge bolt. During the swinging movement,V asrshown in Figs.f-4 and 9, thecam pin A5'- rides on the outer periphery 45d Aof the frame plate and the frame plate acts las a cooking: cam to Yforcethe slide .to moveto the right and wedge theflringpinrback slightly beyondcockd position, whereuponthe Sear snaps in front of thehflangekll. lFurther swinging movement of the frame plate exposes the breech end of the barrel 'and the cam pin 45, engaging a portion ofthe periphery 45a which is progressively less remote from the axis vof the hinge bolt 4.,; returns to the extreme left hand position, as shown in Figs. 5 and 1-0, toserve as a vdetent releasably holding the 'breechin open position.

y With the breech in open position, a fired cartridge rmay be ejected byk means best illustrated in Figs'. 6, l0, and l2. The ejector 48 is slidably mounted in an undercut groove 48a. in the side of the barrel (Fig. 12) and passes rearwardly through the frame plate, where it is provided with a claw 49 forming a movable part of the rim of the chamber and extending beneath the normal position ofthe cartridge rim. An ejector handle 50 is threadably or otherwise attached to the ejector `and projects laterally through ya slot in the actionvtube cover. Within the cover a spring 5l and spring guidey rod 52 engage the ejector handle to urge the ejector into its normal forward position in the direction of the nozzle of the barrel. A rearward movement o-f the handle 50 carries with it vthe ejector and the claw 49 withdraws `a cartridge from the chamber. It will be noted that. both the breech face of the barrel and the extractor claw are counterbored to provided a recess completely enclosing and supporting the head of the cartridge to prevent case casualties with high operating pressures.

Particularly for use with ammunition in which the fasteners are equipped with gas check sabots or'heel caps, such as the' ammunition shown in the c'opending application of Catlin et al., previous'ly referredto, I prefer to counterbore the muzzle section of the barrel as shown in Fig. 1.

` Obviously, if a sabot is to fulfill its function as a gas check, it must t tightly in the bore and since tools of this type are designed to be firedr with the muzzle practically in contact with the workpiece, the heel of the fastener and the sabot thereon will usually remain within the muzzle section of the barrel after ring. If'the snug nt between sabot and barrel is retained all the way vto vthe muzzle, it may be diflicult to remove the tool from a driven fastener or the sabot may pull i off the fastener and remain in the barrel, neither condition being desirable. y v y Occasionally a fastener will be driven so deep that the forward end of the sabot contacts the workpiece and may be deformed thereby almost to the point of complete attening. If this action takes place within a snug tting muzzle section, the sabot will be forced and thermoplastically molded into intimate contact with the barrel and may be difficult to remove therefrom.

Accordingly, I form the counterbored muzzle in two sections consisting of an outer fiared section 51 having a depth about equal to the length of the usual sabot and awidth about equal to the diameter of a sabot flattened under pressure. The .remainder of the'counterbore is cylindrical as at 58,'of a diameter somewhat-larger than that ofthe major part ofV thenbore '59, and of a depth kadequate to receive Vthe undriven portion of the fastener designed topproject from the'f-aceof thek workpiece the greatest amount after beingdriven into the work. Sfuch ay fastener is usually pne which `has `a relatively long, e. g., 2.1/2 Vvinch, threaded shank designed to-be left'exposedafter the pointedv portion has been vdriven into the work. NWith ammun-itionpofdthe type shown in the copending application, frequently referred to lherein,1 have `found that an increase in diameterof aboutl .013"y is adequate to prevent the sabot fromY sticking in the` barrel. With a soft metal sabot a lesser degree of Aenlargement would probably be adequate and with wound paper-.or similar material a greater degree of enlargement would probably,A be required.y After the saboty enters the ceunterbored section, gas escapesby it under high pressure. The violence ofthe re. port obtained on firing is one ofthe limiting factors influencing the choice of the diameter o the counterbore 58. f

It may also be noted that some plastic materials which may be used as sabots have'a tendency to stick lto and build up on the surface of the may be ttedwith a conical guard 53 which may have an insert 54 of neoprene or other rubberlike material. Sucha guard insureslthat fragments can only be projected laterally and, even in that direction, somewhat impedes their` progress by the resistance of the insert. It will bel notedv that the guard is permanently fastenedto the action tube extension and may not be re` c moved without unscrewing the action tube extenfA sion from the action tube. This feature prevents the use of the tool without a guard yand thus insures that a careless operator'm'aynot remove the guard and cause his own injuryfrom spall fragments, ricochets, etc.

For special work in corners, electrical conduitv boxes, adjacent to the flanges of angles or channels, and other locations which may not be readily reached rwith the standard guard illustrated,

several additional action tube extensions, eachV furnished with aspecial guard adapted to the particular job, may be furnished as accessories. Such accessories are not shown in this applica-'- tion, since they function exactly as the standard guard here illustrated and differ only inthe conformationof the work engaging portion offth guard.

The forward end of the action tube extension may conveniently be counterbored as at 55 to accept disks of metal or other material which can be temporarily retained therein by detents 55a formed integrally ywith and projecting inwardly from a spring 56 engaged in a groove 56d encircling the outside of the extension and best hole' therein and making the disk serve as a washe'rion the shankhof the fastener. Sucha disk 7 covers the slight spalling produced at the point of penetration, aids in straight penetration of the fastener, and, by engagement with the enlarged head of a fastener, limits the depth of penetration thereof. They are particularly valuable in fastening wooden members such as furring strips to masonry walls.

In recapitulating, let us assume that with the frame plate 2 in the Figs. 5 and 10Vposition, a loaded cartridge consisting, for example, of a primedand powder charged case, a gas check sabot, and an appropriate type of industrial fastener as disclosed in the copending Catlin application above referred to is loaded into the chamber. The frame plate 2 and parts secured thereto (barrel I, action tube cover 8, action tube 33, and extension 36) may then be turned about the bolt 4 as a pivot into alignment with the breech block 3, housing 9, and parts housed therein as shown in Fig. 1 and latched there by the inter-engagement of the cam pin 45 and notch 46, as shown in Figs. 3 and 8. The guard 53 may then be placed against the face of the work, where it may be accurately located by means of intersecting guide lines scribed on the work and by guide notches formed at 90 spacing on the rim of the guard. The tool may then be forced toward the work to bring the muzzle of the barrel into substantial contact therewith, thus releasing the sear lock 3|. After depressing and holding the safety button 25 with one hand, the trigger may be pulled with the other hand and the fastener will be driven into the work. As explained in the copending Catlin et al. application, a variety of fasteners are usually stocked by a tool user and may be assembled on the job with factory loaded cartridges of appropriate power, each of which may be fitted with a gas check or sabot having a recess fitting the fastener or otherwise capable of releasably engaging same.

After firing, it will usually be found that the gas check remains on the end of the fastener within the counterbored muzzle section of the barrel.

To extract the fired cartridge, the breech of the barrel is first exposed by manual operation of the latch 40 which releases the cam pinv 45 from the notch '45. The frame plate 2, cover 8, barrel I, and parts 35 and 36, are interconnected as a unit, and as a unit they may then be pivoted about the bolt 4 to remove the breech block 3 from a position closing'the chamber in the barrel. During this pivoting of the frame plate about the bolt 4, the surface 45a cams the latch further in to complete the retraction of the firing pin which is then held by the scar.

With the breech end of the barrel exposed, the ejector 48 may be operated by the handle 50 and the claw 49 will remove the fired cartridge from the chamber.

Although a specific embodiment has been here illustrated and described, it should be understood that I consider the invention to extend to all equivalent devices and constructions falling Within the terms of the claims appended hereto.

I claim:

1. An explosively operated tool comprising a barrel; an action tube including a Work-engaging end slidable on said barrel; spring means tending to cause said end of said tube to project in advance of the muzzle of said barrel; firing means to discharge a cartridge chambered in said barrel; a safety lock engaging said firing means t-o block the operation thereof; and a member on said tube and movable therewith,

whenever said end of the tube is forced back a predetermined distance toward the plane of the muzzle of the barrel against the urging of said spring means, into engagement with said safety lock to disengage same from blocking engagement with the firing means.

2. A tool as described in claim 1, said firing means comprising a. firing pin and a movable sear to releasably restrain the firing pin, and said safety lock comprising a movable element removably projected across the path of movement of the sear to oppose movement of the sear to ring pin releasing position.

3. A tool as described in claim 1, in which said action tube comprises a rearward part to which said safety lock engaging member is joined and a forward part having permanently secured thereto a safety guard; an action tube cover xedly mounted on said tool to enclose said rearward part of said action tube and at least a portion of the breech end of said barrel; and a separable connection between said parts of the action tube, said connection being located within said cover and rearward of the muzzle of said barrel so that in the absence of said forward part of the action tube and of the safety guard attached thereto said rearward part of the action tube is inaccessible and said safety lock engaging member cannot be displaced to disengage aid safety lock.

4. In an explosively operated tool including a movable fire control trigger bar, an automatic safety device comprising an eccentric cam pivotally mounted on an axis generally transverse to the line of movement of the trigger bar. spring means tending to rotate the eccentric surface of said cam into frictional engagement with the trigger bar, and manually operable means to rotate said cam against the urging of said spring to a position out of engagement with the trigger bar.

5. An automatic safety device for an explosively operated tool as described in claim 4, said cam being so disposed that the portion thereof having the greatest radius is positioned relative to said axis in a direction substantially opposite to that in which the trigger bar must be pulled to nre said tool, whereby movement of the trigger bar in ring direction when said safety cam in frictional engagement therewith will result in jamming said cam between the trigger bar and said axis.

6. An automatic safety device as described in claim 5, the eccentric surface of said cam and vthe surface of the trigger bar with which it engages being roughened for more positive frictional engagement.

'7. An automatic safety device as described in claim 4, said trigger bar being formed to define trigger portion engageable by an operators finger and said manually operated cam rotating means being so positioned and so remote from said trigger portion as to require a normal operaltor to operate the trigger with one hand and said manually operable cam rotating means with another hand.

8. An automatic safety device as described in claim 4, said spring means and said manually operable means being combined in the form of ra plunger, the spring urging said plunger to project outwardly from said cam and said trigger bar, and a tail on said cam engaged with said plunger to rotate the cam in response to projection or retraction of said plunger.

9. An explosively operated tool comprising a breech block, a frame plate facially engaged with said breech block, a hinge bolt passing through y barrel supported by said frame plate, disengagef ment of said latch permitting said frame plate and breech block to be rotated relative to each other about the axis of said hinge bolt to expose n the breech end of said barrel. l

10. A tool as described in claim 9, including a spring-urged firing pin mounted for sliding movement in said breech block for operation on a cartridge in said barrel, an abutment onsaid firing pin, and a Wedge-like cam on said latch engageable With said firing pin abutment as said latch is moved to disengage from the latching notch on the frame plate to at least partialiy retract said firing pin.

11. A tool as described in claim 10, said frame plate, after disengagement of the latch from the latching notch, being swingable about said hinge bolt to expose the breech end of said barrel, a cam pin on said latch, and a cam surface on said frame plate engageable with said pin during swinging movement of the frame plate to further slide said latch in the same direction as that disengaging the latch from the locking notch to completely cock the firing pin.

12. A tool as described in claim 9, said breech block being provided at a location remote from said hinge bolt With a breech hook, and said frame plate being provided with a recess in which said hook may be engaged to resist separation of the engaging faces of breech block and frame plate when said members are latched in barrel breech closing relationship.

13. A tool as described in claim 9, including a firing pin mounted for sliding movement in said breech block, said iiring pin being urged to move from a cocked Vposition to a released position, a sear engageable with said firing pin to releasably hold same in cocked position, a sear lock engageable with said sear to prevent release thereof, means defining holes in said frame plate and breech block which are in alignment only when said breech block closes the breech end of the barrel, and means including sear lock release means mounted on said barrel, said sear lock release means being operable on said sear lock only by projection through said aligned holes whereby 19 release of said sear from holding engagement with the ring pin is positively prevented except when said breech block closes the breech end of said barrel.

` 14. An explosively operated tool comprising a` breech block, a hinge bolt passing through said breech block, a frame plate hinged on said bolt and confined thereby in interfacial engagement with said breech block but capable of rotation with respect to said breech block about the axis of said hinge bolt, means on said breech block extending beyond the face of said frame plate, defining a hook facing toward said breech block,

means defining a recess in said frame plate facing f away from said breech block and adapted to receive said hook, a barrel mounted in said frame plate in substantial parallelism With said hinge bolt, the breech end of said barrel being opposed by said breech block when said hook is engaged in said recess and exposed when said frame plate has been manually rotated to a position in which said hook is no longer engaged in said recess,

` a manually retractible slide mounted on said breech block, a latch pin on said slide, and lock means in said frame plate engageable by said latchpin when said hook is engaged in the recess 'to releasably latch the frame plate and breech block in barrel breech closing relationship.

15.*A tool as described in claim 14, including a spring-urged firing pin mounted for sliding movement in said breech block arranged to cooperate With a cartridge chambered in the barrel, a flange on said iiring pin, and a wedge-like cam surface on said slide engageable With'said flange to at least partially retract the firing pin from said barrel as said slide is manually retracted to disengage the latch pin thereon from said lock means.

16. A tool as described in claim 15, the outer periphery of said frame plate adjacent to said lock means being shaped to define a cam engageable with said latch pin during manual barrel breech exposing rotation of the frame plate relative to said breech block about the axis of said hinge bolt to further retract said slide and by action of said wedge-like cam on the firing pin ange to complete the cooking of the firing pin.

MERLE H. WALKER.

References Cited in the ile of this patent UNITED STATES PATENTS Sopris Aug. 8, 1950 

